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arXiv · 2311.09026

Metal-free Stoner and Mott-Hubbard magnetism in 2D polymers with honeycomb lattice

Hongde Yu·Thomas Heine
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Abstract

We computationally demonstrate Stoner-ferromagnetic half-metals and antiferromagnetic Mott-Hubbard insulators in metal-free 2D polymers. Coupling radicaloid (hetero)triangulene monomers via strong covalent bonds preserving the in-plane conjugation of the electronic {\pi} system yields 2D crystals with long-range magnetic order and magnetic couplings above the Landauer limit. Dual-site honeycomb lattices produce both flat bands and Dirac cones. Depending on the monomers, electron correlations lead to either a bandgap at the Dirac points for antiferromagnetic Mott insulators, or Stoner ferromagnetism with both spin-polarized Dirac cones and flat bands at the Fermi level. These results pioneer a new type of Stoner and Mott-Hubbard magnetism emerging in the electronic pi system of crystalline conjugated 2D polymers.

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Hongde Yu, Thomas Heine. 2023-11-15. Metal-free Stoner and Mott-Hubbard magnetism in 2D polymers with honeycomb lattice. https://doi.org/10.1126/sciadv.adq7954

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